Malicious PDF — malware analysis report

Static analysis result for SHA-256 563344cf85ead64d…

MALICIOUS

PDF

3.4 KB First seen: 2026-05-10
MD5: 6e57356e173b79328d5264eb0d358f54 SHA-1: a0b34dea53d332c22cd607a0f67b5fdde3bd7e58 SHA-256: 563344cf85ead64d56d6a7aa3d8a6c92eb791730fd3e400a7ce655c5495c10ff
118 Risk Score

Malware Insights

MITRE ATT&CK
T1059.003 JavaScript T1566.002 Spearphishing Attachment

The ML classifier strongly indicates this PDF is malicious. Static analysis detected JavaScript actions and the use of ASCIIHexDecode filters, which are commonly used to obfuscate malicious content within PDFs. These indicators suggest the PDF is likely attempting to exploit a vulnerability to execute JavaScript, potentially leading to further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 3

  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript rebuilds a builtin via replace() to run a char-code array critical PDF_JS_REPLACE_OBFUSCATED_CHARCODE_BUILDER
    Decoded PDF JavaScript resolves a String builtin from a junked literal — e.g. String['eQvoaol3'.replace(/[3oQS5]/g,'')] yielding fromCharCode/eval — and feeds a large numeric char-code array through it to rebuild and execute the next stage. Dynamically reconstructing a builtin name by stripping junk characters has no benign purpose; paired with the char-code payload array it is an unambiguous obfuscated-JavaScript exploit dropper.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes